A man armed with an assault rifle, several hand grenades, smoke bombs and tear gas opened fire on an Atlanta courthouse, where he was scheduled to plead guilty on drug charges Friday. The assault sparked a gunbattle with police that left the assailant dead and a deputy wounded.

The three-minute shootout ended in the death of Denis Marx, 48, according to Forsyth County Sheriff Duane Piper, who says the suspect had a history with the department, including at least two arrests on drug charges.

"Marx also had water and other supplies, including zip ties that can be used to bind people's hands. Piper said the wounded deputy prevented others from getting hurt when he encountered Marx, though it was not clear if that deputy killed the suspect.

"Few details about Marx were known, though Piper said he had been known to authorities for some time. Marx had filed a civil rights complaint against the sheriff's department in 2013, according to court records.

"The complaint accused the sheriff's department of using excessive force and illegal searches. Marx said in the complaint that officers hit him when he was standing with his hands up, used chemical agents to make him believe an explosion or fire had occurred and used an extra set of handcuffs that cut off circulation to his hands."